Motte-and-Bailey Castles

Jean de Colmieu described the typical “motte-and-bailey” castle of northern France:

It is the custom of the nobles of the neighborhood to make a mound of earth as high as they can and then encircle it with a ditch as wide and deep as possible. They enclose the space on top of the mound with a palisade of very strong hewn logs firmly fixed together, strengthened at intervals by as many towers as they have means for. Within the enclosure is a house, a central citadel or keep which commands the whole circuit of the defense.The entrance to the fortress is across a bridge…supported on pairs of posts…crossing the ditch and reaching the upper level of the mound at the level of the entrance gate [to the enclosure].

Requiring no skilled labor, such motte-and-bailey castles were quick and cheap to construct. They had a further advantage in that they were basically independent of considerations of terrain, and could be built anywhere that a fortification was needed. The motte, or mound, was steep-sided, sometimes partly natural, sometimes wholly artificial, formed in part by soil from the encircling ditch. Flat-topped, roughly circular, usually one hundred to three hundred feet in diameter at the base and anywhere from ten to one hundred feet high, the motte was crowned by a wall of timber palisades. The “central citadel or keep” was hardly more than a blockhouse or tower, usually of wood, though occasionally, where stone was plentiful, of masonry. The tower was too small to house more than the lord or the commander (castellan) of the castle and his immediate family, and the entire space of the motte was too restricted to accommodate the garrison with its animals and supplies except on an emergency basis.

Therefore a much larger space was cleared below the motte, given its own ditch and palisade, and connected to the upper fort by an inclined trestle with a drawbridge. This lower court, or bailey, was roughly circular or oval, its exact shape depending on the contours of the land. Sometimes there were two baileys, or even three, in front of the mound or on either side of it. The sense of the arrangement was that the garrison could use the whole interior of motte and bailey for everyday living, secure against minor attacks. In case of a serious threat, the garrison crowded up into the steep-walled motte.

— Daily Life in Medieval Times, Section I, Chapter 1